Angular 单元测试 HTTP 请求标头

Question

我想编写一个单元测试来检查 http 请求的标头。但是，当我尝试访问请求标头时，测试总是以错误结束：

it('should have my header', () => {    
  httpClient.get('/someURL').subscribe();
  const req = httpTestingController.match({ method: 'get' });
  console.log(req[0].request.headers);   
  expect(req[0].request.headers.has('Custom-Header')).toEqual(true);
  httpTestingController.verify();
});

单元测试失败并出现以下错误：

TypeError: Invalid attempt to spread non-iterable instance.
In order to be iterable, non-array objects must have a [Symbol.iterator]() method.

我尝试了各种方法，但我总是在访问标题的“预期”行中收到此错误。当我在控制台中记录标题时，它看起来像这样：

LOG: HttpHeaders{normalizedNames: Map{}, lazyUpdate: [Object{name: ..., value: ..., op: ...}], headers: Map{}, lazyInit: HttpHeaders{normalizedNames: Map{}, lazyUpdate: null, headers: Map{}}}

Answer 1

您的规范中是否还有其他使用扩展运算符的代码？

请参阅下面的工作示例。

import { HttpClient, HttpClientModule, HttpHeaders, HttpRequest } from '@angular/common/http';
import {
  HttpClientTestingModule,
  HttpTestingController,
  TestRequest,
} from '@angular/common/http/testing';
import { TestBed, waitForAsync } from '@angular/core/testing';

describe('headers test', () => {
  let httpTestingController: HttpTestingController;
  let httpClient: HttpClient;

  beforeEach(
    waitForAsync(() => {
      void TestBed.configureTestingModule({
        imports: [HttpClientTestingModule, HttpClientModule],
      })
        .compileComponents()
        .then(() => {
          httpTestingController = TestBed.inject(HttpTestingController);
          httpClient = TestBed.inject(HttpClient);
        });
    }),
  );

  afterEach(() => {
    httpTestingController
      .match((req: HttpRequest<unknown>): boolean => true)
      .forEach((req: TestRequest) => (!req.cancelled ? req.flush({}) : null));
    httpTestingController.verify();
  });

  it('should have my header', () => {
    const headers = new HttpHeaders().set('Custom-Header', 'test');
    void httpClient.get('/someURL', { headers }).subscribe();
    const req = httpTestingController.match('/someURL');
    console.warn('req', req);
    console.warn(req[0].request.headers);
    expect(req[0].request.headers.has('Custom-Header')).toEqual(true);
  });
});